Question: Simplify the following expression: $k = \dfrac{x^2 - 3x - 10}{x + 2} $
Solution: First factor the polynomial in the numerator. $ x^2 - 3x - 10 = (x + 2)(x - 5) $ So we can rewrite the expression as: $k = \dfrac{(x + 2)(x - 5)}{x + 2} $ We can divide the numerator and denominator by $(x + 2)$ on condition that $x \neq -2$ Therefore $k = x - 5; x \neq -2$